With continuous development of wireless telecommunications, more and more users communicate by radio; the current wireless communication is not limited to voice communication, and wider data service communication is a direction of development of the wireless communication system, such as video, service or business data and the like. Along with the daily growing scale of the wireless communication, wireless spectrum resource is more remarkable in short supply. However, the current spectrum allocation system is generally a fixed allocation, that is, fixed spectrum resources are allocated to authorized users, which further increases the situation of the short supply of the spectrum resources. For example, the authorized users do not always occupy the allocated spectrums according to a large number of actual observed results around the world, that is, no matter which wireless access technology is utilized, a part of spectrums are always spare at a certain time within a certain space and frequency band. This provides the possibility for the effective utilization of these spare spectrum resources and for unauthorized users to provide paid service, so that the utilization ratio of the spectrum is increased and the pressure of the spectrum resources is reduced. The Cognitive Radio (CR) technology is developed based the above background.
In the current CR dynamic spectrum allocation technology, the purpose of an optimal dynamic spectrum allocation is achieved through utilizing an optimization algorithm including a neural network, a genetic algorithm, a simulated anneal algorithm or the like based on a method including game theory, tender, graph theory or the like. The above methods have the following shortages of large calculated amount, complex calculation, a lot of wasted device resources, and bad for the fast response of a device; in addition, the frequency bands available for wireless communication in the world are limited at present, and available Radio Access Technologies (RAT) are also limited, such that conclusions obtained by the above algorithms are not necessarily ensured to be actually available and a certain degree of approximation may need to be carried out, which counteracts the advancement of the algorithms to some extent. Another type of the allocation technology is that a Dynamic Spectrum Allocation (DSA) and Handover (HO) are carried out through utilizing the method of searching a database. The key points of the method are a construction of the database and a mechanism of searching the database. The database directly determines the effect of the DSA and the HO, thereby determining performance of a whole communication system.
In a wireless communication network, in particular a heterogeneous wireless communication network, an urgent problem to be solved is that how a CR network utilizes a database with the minimum cost to finish the allocation and the handover of dynamic spectrums.